[Qt-interest] Screenshot

[Tom Panning]

Ankit,

This is almost certainly not worth the effort required. Not only would
you have to disable screenshots and screen-capture programs from
seeing your app, your app would have to be unusable over VNC or remote
desktop (because otherwise someone could VNC to a computer running
your application and take a screenshot of the VNC session).

That being said, I believe it can be done. You need a way to bypass
the normal graphics system write directly to the video hardware. Movie
playback and OpenGL stuff used to have to do this, and if you tried to
take a screenshot of a movie playing, you would just see a blue block
where the movie was. This is no longer the case (taking a screenshot
of a movie or OpenGL application works properly now), but it gives you
an idea of what you would need to do.

Of course, someone can still use a camera to take a picture of the
screen (which wouldn't give a very high quality picture). Or they
could hook the VGA cable to a recording device.

So it all depends on what you're really trying to accomplish. There
may be an easier way to achieve your goals (for instance, if you just
want to prevent people from using the images in your application, you
can try some of the invisible wartermarks).

Tom

On Fri, Jul 24, 2009 at 5:21 AM, Ankit Agarwal<ankit17.ag at gmail.com> wrote:
> Hi,
> I want that the user should not be able to take a screen shot of my
> application.
> One way to prevent this is to re-implement the keyPress() functions and
> check of Print Screen key being pressed but how can I prevent the screenshot
> being taken from a third party tool?
>
> --
> Regards,
> Ankit Agarwal
> Blog : http://ankit17.wordpress.com
>
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